Over the past year nearly all of the 24 subjects planned for the study were run. These subjects underwent functional magnetic resonance imaging (fMRI) before and after administration of IV naloxone, which blocks endogenous opioid receptors. During both scans participants rated their perception of the pleasantness and painfulness of gentle brushing, deep pressure, and heat pain. The study is now nearly complete and we will proceed to analyze the data to see whether the naloxone alters the pleasantness or painfulness of these sensations, and which brain areas are involved in this effect.